{"title":"AlCl4−‐Deficient Eutectic Electrolytes Enable Reversible Iodine Redox‐Amphoteric Conversion for Aluminum Battery Cathodes","authors":"Xingyuan Chu, Shengyue Lu, Shaik Ghouse, Jiaxu Zhang, Arafat Hossain Khan, Jingwei Du, Xiaodong Li, Buyun Gao, Xiaohui Liu, Ahiud Morag, Xinmei Song, Dongqi Li, Leilei Zheng, Quanquan Guo, Mingchao Wang, Eike Brunner, Xinliang Feng, Minghao Yu","doi":"10.1002/anie.202516059","DOIUrl":null,"url":null,"abstract":"Aluminum (Al) batteries are promising for sustainable and large‐scale energy storage due to the inherent safety, low cost, and attractive metrics of the Al anode. However, the development of high‐voltage and high‐capacity cathodes remains a key challenge. Herein, we achieve the reversible iodine redox‐amphoteric conversion (i.e., I<jats:sup>−</jats:sup>/I<jats:sup>0</jats:sup>/I<jats:sup>+</jats:sup>) in Al batteries, wherein AlCl<jats:sub>4</jats:sub><jats:sup>−</jats:sup>‐deficient eutectic electrolytes are identified critical for stabilizing the conversion process. In contrast to ionic liquid electrolytes prone to parasitic Cl<jats:sub>2</jats:sub> evolution, eutectic systems facilitate the I<jats:sup>−</jats:sup>/I<jats:sup>0</jats:sup>/I<jats:sup>+</jats:sup> conversion process with high reversibility and significantly suppressed Cl<jats:sub>2</jats:sub> generation. Spectroscopic and theoretical investigations reveal AlCl<jats:sub>4</jats:sub><jats:sup>−</jats:sup> as the dominant species limiting anodic stability of the electrolyte, and its reduced presence in eutectic electrolytes directly enhances iodine conversion reversibility. The optimized electrolyte allows the I<jats:sub>2</jats:sub> electrode to deliver a specific capacity of 358 mAh g<jats:sup>−1</jats:sup> and an energy density of 490 Wh kg<jats:sup>−1</jats:sup> (based on I<jats:sub>2</jats:sub> mass), along with excellent cycling stability (83.8% retention over 1000 cycles). High‐loading I<jats:sub>2</jats:sub> electrodes (8.52 mg cm<jats:sup>−2</jats:sup>) achieve a high areal capacity of 2.25 mAh cm<jats:sup>−2</jats:sup> and demonstrate practical feasibility in a single‐layer pouch cell. This work establishes a new design framework for high‐energy‐density Al batteries and opens avenues for advancing conversion chemistries in multivalent systems.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"105 1","pages":""},"PeriodicalIF":16.9000,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Angewandte Chemie International Edition","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1002/anie.202516059","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Aluminum (Al) batteries are promising for sustainable and large‐scale energy storage due to the inherent safety, low cost, and attractive metrics of the Al anode. However, the development of high‐voltage and high‐capacity cathodes remains a key challenge. Herein, we achieve the reversible iodine redox‐amphoteric conversion (i.e., I−/I0/I+) in Al batteries, wherein AlCl4−‐deficient eutectic electrolytes are identified critical for stabilizing the conversion process. In contrast to ionic liquid electrolytes prone to parasitic Cl2 evolution, eutectic systems facilitate the I−/I0/I+ conversion process with high reversibility and significantly suppressed Cl2 generation. Spectroscopic and theoretical investigations reveal AlCl4− as the dominant species limiting anodic stability of the electrolyte, and its reduced presence in eutectic electrolytes directly enhances iodine conversion reversibility. The optimized electrolyte allows the I2 electrode to deliver a specific capacity of 358 mAh g−1 and an energy density of 490 Wh kg−1 (based on I2 mass), along with excellent cycling stability (83.8% retention over 1000 cycles). High‐loading I2 electrodes (8.52 mg cm−2) achieve a high areal capacity of 2.25 mAh cm−2 and demonstrate practical feasibility in a single‐layer pouch cell. This work establishes a new design framework for high‐energy‐density Al batteries and opens avenues for advancing conversion chemistries in multivalent systems.
铝(Al)电池由于其固有的安全性、低成本和具有吸引力的铝阳极指标,在可持续和大规模储能方面具有很大的前景。然而,高电压和高容量阴极的开发仍然是一个关键的挑战。在此,我们在铝电池中实现了可逆的碘氧化还原两性转换(即I - /I0/I+),其中AlCl4−缺陷共晶电解质被认为是稳定转换过程的关键。与离子液体电解质容易产生寄生Cl2相比,共晶体系促进了I−/I0/I+的转化过程,具有高可逆性,并显著抑制了Cl2的产生。光谱和理论研究表明AlCl4−是限制电解质阳极稳定性的主要物质,其在共晶电解质中的减少直接提高了碘转化的可逆性。优化后的电解质允许I2电极提供358 mAh g - 1的比容量和490 Wh kg - 1的能量密度(基于I2质量),以及出色的循环稳定性(超过1000次循环保持83.8%)。高负载I2电极(8.52 mg cm - 2)实现了2.25 mAh cm - 2的高面容量,并证明了单层袋状电池的实际可行性。这项工作为高能量密度铝电池建立了一个新的设计框架,并为推进多价系统的转化化学开辟了道路。
期刊介绍:
Angewandte Chemie, a journal of the German Chemical Society (GDCh), maintains a leading position among scholarly journals in general chemistry with an impressive Impact Factor of 16.6 (2022 Journal Citation Reports, Clarivate, 2023). Published weekly in a reader-friendly format, it features new articles almost every day. Established in 1887, Angewandte Chemie is a prominent chemistry journal, offering a dynamic blend of Review-type articles, Highlights, Communications, and Research Articles on a weekly basis, making it unique in the field.